Safety-fuse.



No. 874,797. PATENTED DEC. 24, 1907.- J. SACHS & P. I). REYNOLDS.

SAFETY FUSE.

APPLIOATION FILED APR. 1a, 1906. RENEWED JUNE 15. 1907.

Wi J E55 :5 a

UNITED STATES PATENT OFFICE.

JOSEPH SACHS AND FRANK D. REYNOLDS, OF HARTFORD, CONNECTICUT, ASSIGNORS T 0 THE SACHS COMFANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

SAFETY-FUSE.

Specification of Letters Patent.

Patented Dec. 24, 190?.

Application filed April 18-1906, Serial No. 312.303. Renewed'June'l5.1907. Serial in. 379.181.

which thefollowing is a specification.

Our invention relates to safety fuses and particularly to that classof safety fuses commonly known as indicating inclosed fuses.

Heretofore, indicating fuses .have been constructed with an indicator wire wholly on the exterior of the fuse casin .or the indi-' cator wire has been essential y within the casing with an indicating portion extending to the exterior surface -thereof. In still other instances the indicator wire has been employed entirely within the fuse casing and means have then been associatedtherewith and situated in the walls of the casing or extending through the said walls to indicate the rupture of the fuse strip. 7 In all of these instances however, so. far as we are aware,

the indicator wire, either directly or indirectly, has been the means for indicating the rupture of the fuse stri As shown and descri ed in our co-pending application Serial No. 310,045,. filed April 5th, 1906, we have invented an indicator for pass directl through the end cap, so as to be inclosed safety fuses in which we employ an indicating connection forming art of a-circuit shunted across the'termina s of the fusedevice and located between the inside of an end cap and the tube, whereby'we obtain a direct, positive and clear indication of the blowing of the fuse. Now in our present invention, we have rovided a similarly simple construction a so embodyin an indicatmg means electrically interpose between an end cap and one end of a conductor electrically connected at the other endto the other end ca In this case, the indicating means visible on t e outer surface thereof and comprise or lnclude a conducting lndicatmg con-' nection e'lectricall T connected with the end ca and one end 0 the conductor. f I

- ncan'ymg out our present invention, we employ a tube or casmg, end ca s therefor, a

fuse strip electrically connecte to said'end caps, a conductor connected at one end'to one vof said "end caps, and ,an1indioatingf means, includinga conducting-connection,

electrically interposed between the other end cap and the other end of thesaid conductor,

and extending through the end cap to the visible surface thereof; The indicating means extending to the surface of the end cap may may extend to the surface of the end cap and be of such a material as to be merely changed in appearance by the heating, burning, disrupt on or other effect caused by;the current, or this connection may extend only part way to the surface of the end cap and may be covered by a lug or other means which is ejected'by t. e disruption of the connection as will be hereinafter more particularly described.

In the drawing, Figure 1 is a central longitudinal section of a safety fuse embodying our present invention. Fig 2 is a plan of the same. Fig. 3 is a central longitudinal section showing. amodified form of our in-' vention. Fig. 4 is an elevation of the left hand end of the device shown in Fi 3, and Figs. 5 and 6 are end sections of modifications of the invention. a designates atube made of any .suitable insulating material, the ends of which we provide with suitable ferrules or end caps b, to which are electrically connected fuse terminals c and extending between the fuse terminals 0 and electrically connected therewith, We employ a fuse strip (i.

Referring particularly to Figs. 1 and 2, oneof the end caps 12 is shown as provided with a suitable o ening adapted to receive a plug 2'. The p ug 2 is preferably passed through the body 0 the end cap I; and into and partially through the adjacent portion of the tube a, the outer end of the plug being flush with the surface of the body of the end cap. I V

e designates-a wire elebtrically connected at one end to one of the end ca s, b, which wire 0 is passed longitudinally t rough thetube a, through an aperture therein 1mme diately below the recess provided for the reception of the plug 2, and is electrically connected atits o posite end with the said plug 2, which may be made of carbon, graph- 1te or'other simi ar substance or a mixture of the same and a substance such as -gunfurther I powder which will burn, discolor or otherwise change in appearance when heated by the current passing through it upon the blowing of the fuse, thereby providing an indicating conducting connection interposed between the end cap and one end 'of the conductor e and this plug may be of definite form before it is placed in the opening or it may be of plastic material which is molded into the opening and adapted to dry and harden therein. This is the preferred form of our invention, and in order to make a clearer-indication we may whiten or otherwise color the visible portion of the indicating connection. Or as indicated in Figs. 3 and 4, we may employ a conical plug of graphite or carbon indicated at 4 adapted to ht into an aperture'provided therefor in the end face of one of the end caps 12, and this conical plug may be provided with a shank 5 to which one end of the shunt circuit wire 6 is wound, soldered, or otherwise electrically secured to make connection between these parts, the opposite end of the wire e being electrically connected to the other end cap I) by being carried over the edge of the opposite end of the tube a. and brought into contact with the inner surface of the end cap received thereon or otherwise. In this modiiication of the invention the plug 4 comprises a portion of the indicatin means which are completed by the disrupti lejoint between the end of the conductor 6 and the shank 5 of the plug 4, wherein as will be a parent, the indicating means are electrical y interposed between the end cap and the end of the conductor e, and that upon the disrupting of the joint after the blowing of the fuse, the plug will become loose or fall out of place to indicate such a condition.

As shown in Fig. 5, the plug 2 of graphite or other material may extend only part way through the aperture in the end cap and the remainder of the aperture be filled with an auxiliary plug 6, made of any suitable material, by which the blowing of the fuse is indicaled. In this instance, as will be apparent, that while the conducting connection or lug 2 does not extend to the visible surface 0 the end cap, the indicating means comprising this plug 2 and the auxiliary plug 6 do so extend to the surface of the end cap. In this construction the material of the plug 2 may he of a conducting explosive nature such as a mixture of graphite and gunpowder which when heated by the current disrupts and blows out the plug 6.

Then again and as is shown in Fig 6, we may without departing from the nature and spirit of our invention, place a small quan tity of gunpowder or other explosive material 7 at the base of the aperture in which the plug 2 is placed and beneath the said plug in order to forcibl eject the same upon the blowing of the se.

end cap.

WVe may also employ a filling of insulating material in a loose condition within the tube, as indicated by the letter f.

\Ne claim as our invention:

1. A safety fuse comprising a tube, termitween one of the said end caps and one endof the said conductor and'located at the aperture in the end cap.

3. A safety fuse comprising a tube, terminals thereon, a fuse strip, a conductor, and an indicating connection'electrically interposed between'one terminal and one end of the said conductor and extending into an aperture in the said terminal.

4, A safety fuse comprising a tube, en

caps therefor, a fuse strip, a conductor, and

an indicating connection electrically interposed between one end cap and one end of the said conductor and extending into an aperture in said end cap.

5. A safety fuse comprising a tube, terminals therefor, a fuse strip, a conductor, and an indicatin means inte osed between one terminal an one end of he said conductor and extending into an aperture in the said terminal.

6. A safety fuse comprising a tube, end

caps therefor, a fuse strip, a conductor, and an indicating means interposed between one end cap and one end of the said conductor and extending 7. A safety fuse comprising a tube, terminals therefor, a fuse strip, a conductor, and an indicatin means interposed between one terminal and one end of the said conductor and extending through an aperture in the terminal to the visible surface thereof.

8. A safety fuse comprisin a tube, terminals thereon, a fuse strip electrically connected to the said terminals, a conductor electrically connected at one end to one of the said terminals, the other terminal being provided with an aperture, and an indicating connection electrically inter osed between the said other terminal and t e other end of the said conductor and extending into the said a erture.

9. safety fuse comprisin a tube, terminals thereon, a fuse strip e ectrically connected to the said termlnals, a conductor electrically connected at one end to one of the said terminals and an indicating means electricall interposed between the other terminal an the other end of the said eonduc into an aperture in the said swipe:

torsnd extendin through en eperture in the said other terminel to the visible surfece .thereof.

A safety fuse comprising a tube, terminals therefor, one of which is provided with an aperture, a; fuse strip, a conductor, and a,

plug. of conducting material electrically interposedbetween one terminal and one end Of the said conductor and located at the said aperture in the terminal. p i

" 11. A safetyfuse'comprising a tube, end

, caps therefor, a fuse strip, a conductor, and e eperture in the said terminal.

ture in the said terniina, ffece thereof.

plug of conducting materiel electrically interposed between one terminal and one end ofthe said conduc'torand extending into an 12'. A sefety'fusecomprising a tube, end

caps therefor, a conductor, and a, plug of con ductingmaterial electrically interposed between one terminal and one end ofthe seid conductor and extendin athrough an eper- 13. A safety fuse comprising a tube, end

caps therefor, a fuse strip, a conductor, con- 7 nected at one end to one of said end caps, and

to the visible suron indicetin connection of resistance meteriel electrics ly interposed between the other 1 end of said conductor and the other end can and located in an aperture in said other esp.

ceps therefor, a fuse strip, a conductor directly' connected at one end to one of said end caps; and en indicating connection coInposed of combustible and conducting Insterialelectricelly interposed between'the other 1ft. A safety fuse, coniprising a tube, end 7 end of said conductor, and the other end cap and located in an aperture in said end cap.

15. A safety'fuse comprising a tube, end

anindicating connection electrically inter posed between one endof said conductor and one end cap and located in an aperture in said end esp, and which is visibly. changed upon the rupture of said fuse strip.

40 vceps therefone fuse strip, a conductor, and 

